gcc's unused warnings which don't get emitted if the function is referenced even in an unevaluated context
(e.g. in templates, sizeof, etc.). Also, saying that a function is 'unused' because it won't get codegen'ed
is somewhat misleading.
- Don't emit 'unused' warnings for functions that are referenced in any part of the user's code.
- A warning that an internal function/variable won't get emitted is useful though, so introduce
-Wunneeded-internal-declaration which will warn if a function/variable with internal linkage is not
"needed" ('used' from the codegen perspective), e.g:
static void foo() { }
template <int>
void bar() {
foo();
}
test.cpp:1:13: warning: function 'foo' is not needed and will not be emitted
static void foo() { }
^
Addresses rdar://8733476.
llvm-svn: 129794
CL_AddressableVoid is the expression classification used for void
expressions whose address can be taken, i.e. the result of [], *
or void variable references in C, as opposed to things like the
result of a void function call.
llvm-svn: 129783
rewriting the literal when the value is integral. It is not uncommon to
see code written as:
const int kBigNumber = 42e5;
Without any real awareness that this is no longer an ICE. The note helps
automate and ease the process of fixing code that violates the warning.
llvm-svn: 129243
definitely have a path leading to them, and possibly have a path leading
to them; reflect that distinction in the warning text emitted.
llvm-svn: 129126
marked explicitly as uninitialized through direct self initialization:
int x = x;
With r128894 we prevented warnings about this code, and this patch
teaches the analysis engine to continue analyzing subsequent uses of
'x'. This should wrap up PR9624.
There is still an open question of whether we should suppress the
maybe-uninitialized warnings resulting from variables initialized in
this fashion. The definitely-uninitialized uses should always be warned.
llvm-svn: 128932
int x = x;
GCC disables its warnings on this construct as a way of indicating that
the programmer intentionally wants the variable to be uninitialized.
Only the warning on the initializer is turned off in this iteration.
This makes the code a lot more ugly, but starts commenting the
surprising behavior here. This is a WIP, I want to refactor it
substantially for clarity, and to determine whether subsequent warnings
should be suppressed or not.
llvm-svn: 128894
1) Change the CFG to include the DeclStmt for conditional variables, instead of using the condition itself as a faux DeclStmt.
2) Update ExprEngine (the static analyzer) to understand (1), so not to regress.
3) Update UninitializedValues.cpp to initialize all tracked variables to Uninitialized at the start of the function/method.
4) Only use the SelfReferenceChecker (SemaDecl.cpp) on global variables, leaving the dataflow analysis to handle other cases.
The combination of (1) and (3) allows the dataflow-based -Wuninitialized to find self-init problems when the initializer
contained control-flow.
llvm-svn: 128858
Note this can potentially be enhanced to detect if the __block variable
is actually written by the block, or only when the block "escapes" or
is actually used, but that requires more analysis than it is probably worth
for this simple check.
llvm-svn: 128681
which versions of an OS provide a certain facility. For example,
void foo()
__attribute__((availability(macosx,introduced=10.2,deprecated=10.4,obsoleted=10.6)));
says that the function "foo" was introduced in 10.2, deprecated in
10.4, and completely obsoleted in 10.6. This attribute ties in with
the deployment targets (e.g., -mmacosx-version-min=10.1 specifies that
we want to deploy back to Mac OS X 10.1). There are several concrete
behaviors that this attribute enables, as illustrated with the
function foo() above:
- If we choose a deployment target >= Mac OS X 10.4, uses of "foo"
will result in a deprecation warning, as if we had placed
attribute((deprecated)) on it (but with a better diagnostic)
- If we choose a deployment target >= Mac OS X 10.6, uses of "foo"
will result in an "unavailable" warning (in C)/error (in C++), as
if we had placed attribute((unavailable)) on it
- If we choose a deployment target prior to 10.2, foo() is
weak-imported (if it is a kind of entity that can be weak
imported), as if we had placed the weak_import attribute on it.
Naturally, there can be multiple availability attributes on a
declaration, for different platforms; only the current platform
matters when checking availability attributes.
The only platforms this attribute currently works for are "ios" and
"macosx", since we already have -mxxxx-version-min flags for them and we
have experience there with macro tricks translating down to the
deprecated/unavailable/weak_import attributes. The end goal is to open
this up to other platforms, and even extension to other "platforms"
that are really libraries (say, through a #pragma clang
define_system), but that hasn't yet been designed and we may want to
shake out more issues with this narrower problem first.
Addresses <rdar://problem/6690412>.
As a drive-by bug-fix, if an entity is both deprecated and
unavailable, we only emit the "unavailable" diagnostic.
llvm-svn: 128127
enumeration type to another in C, classify enumeration constants as if
they had the type of their enclosing enumeration. Fixes
<rdar://problem/9116337>.
llvm-svn: 127514
expressions. Consider the code:
int64_t i = 10 << 30;
This compiles fine, but most developers expect it to produce the value
for 10 gigs, not -2 gigs. This is actually undefined behavior because
the LHS is a signed integer type.
The warning is currently gated behind -Wshift-overflow.
There is a special case where only the sign bit is overridden that gets
a custom error message and is by default ignored. This case is much less
likely to cause observed buggy behavior, it's just undefined behavior
according to the spec. This warning can be enabled with
-Wshift-sign-overflow.
Original patch by Oleg Slezberg, with style tweaks and some correctness
fixes by me.
llvm-svn: 126342
several ways. We now warn for more of the return types, and correctly
locate the ignored ones. Also adds fix-it hints to remove the ignored
qualifiers. Fixes much of PR9058, although not all of it.
Patch by Hans Wennborg, a couple of minor style tweaks from me.
llvm-svn: 126321
diagnostics that occur in unreachable code (e.g., -Warray-bound).
We only pay the cost of doing the reachability analysis when we issue one of these diagnostics.
llvm-svn: 126290
Argyrios Kyrtzidis